Continued surveillance of the occurrence of malignant mesothelioma using SEER data for l980 substantiated an earlier finding of increased incidence during the l970s. Elevated risk of bladder cancer has been observed in truck drivers, taxicab drivers, bus drivers, deliverymen and tool and die makers. Breast cancer patients treated with adjunctive radiotherapy were at increased risk of developing a second breast cancer after l0 years of survival. Excess risk of leukemia was observed amoung uterine corpus patients who received radiotherapy. The five-year survival rate for acute lymphocytic leukemia (ALL) among children diagnosed during l973-75 in SEER areas was 50 percent. The increase in 3-year survival rates (59% to 7l%) for childhood ALL from l973-75 to l976-77 was statistically significant. The survival advantage of white over black patients with cancer of the uterine corpus was sustained even after adjustment for histologic type (sarcoma vs. adenocarcinoma), age and stage. Parity was found to be an important prognostic factor in young (less than 36) breast cancer patients with survival inversely related to number of children. Research in theoretical statistical modeling has led to a procedure for determining the appropriate frequency of screening for use in trials of methods for early detection of cancer.